1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to a timing controller that communicates with a source driving integrated circuit (IC) in a point-to-point (an embedded clock point-point interface (EPI)) scheme, a driving method thereof, and an LCD device using the same.
2. Discussion of the Related Art
With the advance of various portable electronic devices such as mobile communication terminals, smart phones, tablet computers, notebook computers, etc., the demand for flat panel display (FPD) devices applicable to the portable electronic devices is increasing. Liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission display (FED) devices, organic light emitting display devices, etc. are being actively researched as the FPD devices.
In such FPD devices, the LCD devices are being most widely commercialized at present because the LCD devices are easily manufactured due to the advance of manufacturing technology and realize drivability of a driver and a high-quality image.
LCD devices adjust a light transmittance of liquid crystal with an electric field to display an image. To this end, the LCD devices include a liquid crystal panel in which a plurality of pixels are arranged as a matrix type, and a driving circuit for driving the liquid crystal panel.
FIGS. 1A and 1B are exemplary diagrams illustrating a configuration of a related art LCD device. FIG. 1A illustrates an LCD device having a general bezel structure, and FIG. 1B illustrates an LCD device having a narrow bezel structure.
FIGS. 2A and 2B are exemplary diagrams for describing a related art EPI scheme.
The related art LCD device includes a panel 10 in which a plurality of data lines and a plurality of gate lines are formed to intersect each other, a source driving IC 30 that supplies data voltages to the respective data lines, a gate driving IC (not shown) that supplies a scan signal to the gate lines, and a timing controller 40 that controls the source driving IC and the gate driving IC.
Recently, in addition to a function of LCD devices, a design of the LCD devices is being actively researched.
When purchasing an LCD device, users determine whether to purchase the LCD device in consideration of a design of the LCD device as well as a function of the LCD device.
In terms of a design of LCD devices, narrow bezel technology for decreasing a bezel is being actively researched.
A bezel 12, as illustrated in FIGS. 1A and 1B, denotes an outer portion of a display area 11 displaying an image in the panel 10. A narrow bezel denotes a bezel having a narrow width, and the narrow bezel technology denotes technology for forming the bezel.
The narrow bezel may be implemented by using a non-double rate driving (DRD) scheme instead of a DRD scheme.
The DRD scheme was developed as one scheme for decreasing the number of source driving ICs. By using the DRD scheme, the number of gate lines increases at two times the number of existing gate lines, and the number of data lines is reduced by half. Therefore, despite the number of necessary data driving ICs being reduced by half, the same resolution as the existing resolution is realized.
The DRD scheme may be implemented by using an interface using an EPI scheme.
Generally, examples of a communication scheme between the timing controller 40 and the source driving IC 30 includes a point-to-point scheme which is as illustrated in FIGS. 1A and 2A and a mini-low voltage differential signaling (LVDS) scheme which is as illustrated in FIGS. 1B and 2B.
The point-to-point scheme is referred to as an EPI scheme. The EPI scheme is a scheme in which the timing controller 40 and the source driving IC 30 perform one-to-one communication. Therefore, in the EPI scheme, the number of output ports of the timing controller 40 should be provided in proportion to the number of source driving ICs 30.
In the mini-LVDS scheme, as illustrated in FIG. 2B, a plurality of source driving ICs are connected to the timing controller 40 in parallel. Therefore, in the mini-LVDS scheme, even though the number of source driving ICs 30 increases, the number of output ports of the timing controller 40 does not increase.
The EPI scheme, as described above, was proposed for implementing the DRD scheme, and is better than the mini-LVDS scheme in implementing the DRD scheme.
However, as described above, since the narrow bezel is implemented by using the non-DRD scheme instead of the DRD scheme, the use of the mini-LVDS scheme is more increasing than the EPI scheme suitable for the DRD scheme.
That is, unlike the mini-LVDS scheme, in the EPI scheme, as the number of source driving ICs increases, the number of ports of the timing controller 40 increases in proportion thereto. Therefore, in LCD devices having a high resolution, the mini-LVDS scheme is better than the EPI scheme in realizing the narrow bezel. For example, as illustrated in FIGS. 1A and 1B, a width A of a bezel connected to the source driving IC 30 in panels using the EPI scheme is formed greater than a width B of a bezel connected to the source driving IC 30 in panels using the mini-LVDS scheme.
To provide an additional description, instead of a method of strengthening advantages of the DRD scheme, a method of realizing the narrow bezel is recently attracting much attention, and thus, the use of the EPI scheme suitable for the DRD scheme decreases.
With such a trend, LCD devices using the non-DRD scheme and including eight source driving ICs are being recently developed.
Since the use of the EPI scheme decreases as described above, conventionally developed timing controllers for the EPI scheme are discarded.
That is, the EPI scheme is for the DRD scheme, and a related art LCD device using the EPI scheme may drive a panel by using, for example, only four source driving ICs. However, in order to realize the narrow bezel, by using the non-DRD scheme instead of the EPI scheme, eight source driving ICs are again used.
Therefore, the related art timing controllers, which include only a certain number (four) of ports equal to the number of source driving ICs so as to use the DRD scheme and the EPI scheme, are not applied to the non-DRD scheme and the mini-LVDS scheme which uses eight source driving ICs.
Among two timing controllers applied to LCD devices having the same resolution, the number of ports of a timing controller using the EPI scheme proposed for the DRD scheme corresponds to half of the number of ports of a timing controller using the mini-LVDS applied to the non-DRD scheme. Therefore, the timing controller using the EPI scheme developed for the DRD scheme is not applied to LCD devices which are implemented by using the non-DRD scheme for realizing the narrow bezel, and is discarded.
As described above, the related art timing controller using the mini-LVDS scheme has ports more by two times than a timing controller using the EPI scheme. Therefore, if the related art timing controller using the mini-LVDS scheme is used as-is for realizing the narrow bezel, a size of a printed circuit board (PCB) with the timing controller mounted thereon increases, the manufacturing cost of the timing controller increases due to the increase in the number of ports, and a process of manufacturing the timing controller and a process of mounting the timing controller become complicated.